Industrial truck



Feb. 2, 1954 H. D. WOUGHTER 2,667,985

INDUSTRIAL TRUCK Filed Sept. 10, 1949 2 Sheets-Sheet l anew Feb. 2, 1954 H. D. WOUGHTER INDUSTRIAL TRUCK Filed Sept. 10, 1949 2 Sheets-Sheet 2 O O O 0 O O Snoentor (Ittomegs Patented Feb. 2,1954

UNITED STATES TENT OFFICE INDUSTRIAL TRUCK Holden D. Woughter, Flint, Mich, assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Application September 10, 1949, Serial No. 114,977

12 Claims. (Cl. 214-670) Warehousing of stacked pallet loads in rows with the open storage space in the row. The lift with access aisles between rows necessitates infork with its loaded pallet is first positioned at sertion and removal of individual pallet loads the desired level and then projected from the in a direction laterally of the aisle and between truck into the storage position. Thereafter the adjoining stacks. If a motor driven material hanfork itself is lowered slightly to deposit the pallet dling truck must be manipulated to make a right either on the floor or in stacked relation to anangle turn in the aisle its overall length calls for other load, as the case may be, and is then rea wide aisle even though the truck has a short tracted in a straight line until it is fully beyond turning radius and because the conventional lift the pallet whereupon the truck may be swung in fork overhangs or projects beyond the wheel the aisle and driven away.' base. A wide clearance aisle represents lost stor- For removing a pallet from any selected storage are age position in a row the truck with its lift fork To conserve space by the use of a narrow aisle retracted is brought into alignment with the it is here proposed to provide a lift truck which pallet and then in succession the fork is projected can be turned in an aisle only slightly larger in a straight line under the pallet; is raised to than the truck wheel base and whose lifting fork pick up the load and retracted to bring the loaded can be retracted during normal truck travel and fork outside the storage row whereupon the truck projected during loading and unloading operais ready to be turned and driven through the tions with components so arranged that the aisle. Straight line projection and retraction of Weight of the overhanging projected fork and the lift: fork is of importance for proper hanits load is properly balanced to preclude tipping dling of pallets and the unobstructed fork reof the vehicle. More particularly the improved eivins pocket is of p i l i ifi n e in conneclift fork is constructed for the projection and retion with the deposit and pickup of loads directly traction of the lift fork on a continuous straight pon the floor. line Whether at its lowest height scraping the For a better explanation of the invention referfloor or at any selected elevated stacking posiones will be made to the accompanying drawings men. I wherein Figure 1 is a side of elevation of the Essentially the load carrying lift fork or platimproved industrial truck with the lift fork form is telescopically mounted for travel in a shown in full lines projected under a pallet resthorizontal plane relative to the wheeled main ing on the door and with other retracted positions frame of the truck. of the fork shown by broken lines; Figure 2 is To provide for straight line travel immediately a top plan view showing the fork projected in adjacent the floor level the main frame has an full lines and retracted in broken lines; Figure 3 open ended and vertically unobstructed pocket is an end elevation with parts in section as on to receive the load carrying fork assembly. The line 33 of Figure 1; Figure 4 is an enlarged pocket is afforded by constructing the main frame view with parts broken away showing the travelin a form substantially U-shape, the legs of ingcarriage for the lift fork assembly and Figwhich are supported at their free ends on ground ure 5 is a transverse section taken on line 5-5 engaging wheels and constitute transversely of Figure 4. spaced apart rails or tracks for the lift forkas- In the drawings the main frame of the wheeled sembly. The cross bar of the U at the opposite truck is generally i the fo o a aD the end of the frame is also supported on ground enp oject l s of which are transverselysp gaging wheels and affords a mounting for the apart and each consists of a pair of longitudinally motor driven unit opposite the open end of the x nding ha l r n i nd 2 r nged back pocket. The transverse spacing of the main t k, as best seen in Figure 5. At their free frame side rails is such that the loading fork ends the sid rails' r h mo d n r und can be lowered to the fioor and lie entirely been ing Wheels 3-3 and at their opposite ends tween the side rails. With the fork in its rethe rails are i t h n h p e betracted position the load being transported is tween them is brid d by transverse frame mempositioned above the main frame and between the s m d 011 One 0 more ible Wheels m; and rear l 7 a 5. A steering handle 6 is provided for a dirigible For unloading in a spot beside an aisle the truck is driven through the aisle to the unloading spot and is then turned transversely of the aisle to bring its projectable fork into alignment wheel assembly and this handle also mounts the controls for the drive motor mechanism by which the steerable wheel is driven when the vehicle is power operated. The drive unit contemplated will include an electric motor and suitable storage batteries, the latter of which may be housed within a suitable container 1 supported on the cross bar of the main frame. The drive unit is thus located at one end of the vehicle and its weight stabilizes the vehicle in that the vehicle will not tip in unloading of the projected lift fork. Also mounted at the power unit end of the vehicle is an electric motor 8 which has a chain drive for a pair of sprockets, one of which is shown at 9 in Figure 1. These sprockets are located at the two sides of the vehicle each in the space between the channels 1 and 2 of the side rails. An endless chain or cable I is engaged by each sprocket and engages at the opposite end of the main frame with a sprocket II, as seen in Figure l. Two links in the upper reach of the chain are secured by pins l2 to a, traveling carriage member [3, one tracking on each of the side rails by means of an upper roller [4 which rides on the top surfaces of the upper flanges of the rails i and 2 and one or more lower rollers are shown at l5 to track on the underside of the innermost channel 2. The carriage also includes the side uprights N5 of a lift tower by which is guided and supported the pallet engaging lift fork or load carrying platform. As shown in the drawings the. forks include a pair of L-shaped members ll transversely spaced apart with their horizontal legs providing the load carrying forks and their vertical legs being tied together by cross bars 18-48 which are guided by the tower risers I5 and are suspended by elevating mechanism, including the chains l9. By controlling the lift mechanism the load supporting platform may be lowered to the floor or raised to any selected height within the limit of the supporting tower. Similarly the lift fork, together with its tower and through its supporting carriage and drive chain H3, may be moved fore and aft between a fully projected position for picking up or depositing a pallet and a fully retracted position within the pocket formed between the side rails of the main frame. Any conventional mechanism may be utilized for operating the lift tower and if desired the lift tower may additionally be arranged for a slight forward and backward tilting movement. However, for most purposes a non-tilt tower will be found satisfactory, particularly since the structure enables the lift fork to be dropped to the floor in all fore and aft positions, including the fully retracted position, sufi'lcient clearance space being provided transversely between the edges of the forks and the adjoining edges of the side frame members.

Whenever the retracted fork carries a pallet which it is desired to deposit on the floor the truck is steered into place transversely of the aisle and the fork is then projected into the storage space and there lowered to deposit and clear the pallet and is withdrawn in a straight line which is in a plane horizontal to the floor line. When fully retracted the fork will be clear of the pallet and the truck may then be turned in the aisle. With no overhang beyond the main frame a minimum of turning clearance will enable the use of narrow aisles.

Similarly when a pallet is to be stacked on a previously deposited load the lift fork is raised to the proper height and after being projected to deposit the load it is withdrawn from under the pallet on a straight line to fully retracted position before the truck is swung in the aisle.

The procedure is reversed for picking up loads and again the direction of travel or projection of the fork is on a straight line under the pallet. In the normal travel of the vehicle the load is carried largely within the wheel base and distributed between the front and rear wheels.

I claim:

, 1. In a material handling vehicle, a main frame having a portion thereof projecting longitudinally from one end of said vehicle to provide an unobstructed space centrally thereof with an open mouth at one end of the main frame, said space being open vertically from the ground up, road wheels mobily supporting said main frame and positioned on said frame adjacent said open mouth for longitudinal movement and a load carrying platform of a size substantially corresponding to said space and movably mounted on the frame at the sides of said space in telescopic relation therewith for the projection and retraction of the platform through said mouth and into and out of the space, the arrangement being such as to enable platform retraction and projection throughout the entire length between its opposite limits of travel to occur in a plane parallel to and immediately adjacent the floor line engaged by said wheels.

2. In a lift truck for load carrying pallets and the like, a wheeled frame having a pair of transversely spaced side rails projecting from one end thereof affording a vertically unobstructed pocket therebetween extending upwardly from the ground, a carriage mounted to ride to and fro horizontally on said rails into and out of said pocket and a pallet lift platform constituting a part of the carriage, said vertically unobstructed pocket enabling the lift platform to be lowered through the pocket to ground level and to be projected and retracted on a straight line at such level.

3. A material handling vehicle especially adapted for use in the storage of low ground clearance pickup loads beside an aisle comprising a truck having front and rear ground. wheels and being longitudinally separated into a rear power unit section and a front load transporting section, said load transporting section including a pair of transversely spaced side rails supported on said front ground wheels, the space between said rails being vertically and laterally unob-.. structed forward of said power unit section, a loading platform of a size substantially corresponding to said space, and platform supporting guides tracking on said rails and providing horizontally telescopic travel of the platform into and out of said space adjacent the ground for load-v ing and unloading operations while the vehicle itself is stationary.

4. In a material handling vehicle, a wheeled truck having a frame, parallel spaced rails projecting from one end of said-frame to form a 'U-shaped pocket Whose mouth is at one end of the truck frame and which within the sides of the pocket is entirely free of vertical obstruction from the ground up, and a retractible-projectable load carrying platform of a longitudinal size substantially corresponding with the length .of said pocket, said platform being telescopically mounted on the truck for vertical travel through the pocket to positions adjacent the ground and horizontal travel to and from a retracted position entirely within the longitudinal extent of the pocket at any vertical position of said platform, the top of said rails being substantially the same height as the top of said platform when in its lowered position.

5. A material handling vehicle especially adapted for use in the storage of low ground clearance pickup loads beside an aisle comprising a truck having a power unit section and a load transporting section, said load transporting section including a pair of rails projecting outwardly from said power section in parallel spaced relation, the space between said rails forming an open ended pocket vertically unobstructed from the ground up, platform supporting guides track-' ing on said rails, and a vertically movable load platform of a size substantially corresponding to said space mounted on said guides for horizontal telescopic travel into and out of said space adjacent the ground for loading and unloading operations while the vehicle itself remains stationary, said rails being disposed at substantially the same height as said load platform when in its lowered position.

6. A material handling vehicle especially adapted for use in the storage of low ground clearance pickup loads beside an aisle comprising a truck having front and rear ground wheels and being longitudinally separated into a rear power unit section and a front load transporting section, said load transporting section including a pair of transversely spaced side rails disposed longitudinally of said vehicle and projecting forwardly from said power unit section adjacent the ground, said front ground wheels being disposed adjacent the outer ends of said side rails to support said load transporting section, the space between said rails being vertically and laterally unobstructed forward of said power unit section from the ground up, a load platform of a size substantially corresponding to said space, and platform supporting guides tracking on said rails and providing telescopic travel of said platform in a substantially horizontal plane into and out of said space adjacent the ground for loading and unloading operations while the vehicle itself remains stationary.

7. A material handling vehicle especially adapted for use in the storage of low ground clearance pickup loads beside an aisle comprising a truck longitudinally separated into a rear power unit section and a front load transporting section, said power unit section having dirigible road wheels disposed thereunder for supporting said power unit section, said load transporting section including a pair of transversely spaced side rails disposed longitudinally of said vehicle and projecting forwardly from said power unit section adjacent the ground, a horizontal axle mounted transversely on each of said rails adjacent the outer ends thereof, a road wheel mounted on each of said axles for rotation in a vertical plane disposed longitudinally of said vehicle, the space between said rails being vertically and laterally unobstructed forward of said power unit section from the ground up, a load platform of a size substantially corresponding to said space, and platform supporting guides tracking on said rails and providing telescopic travel of said platform in a substantially horizontal plane into and out of said space adjacent the ground for loading and unloading operations while the vehicle itself remains stationary.

8. A material handling vehicle especially adapted for use in the storage of low ground clearance pickup loads beside an aisle comprising a truck having front and rear ground wheels and being longitudinally separated into a rear power unit section and a front load transporting section, said load transporting section including a pair of transversely spaced side rails supported on said front ground wheels, the space between said rails being vertically and laterally unobstructed forward of said power unit section, a carriage movably mounted on said rails, a load lifting and carrying platform supported by said carriage for vertical movement thereon independently of the longitudinal position of said carriage, said carriage being adapted for longitudinal movement on said rails to move said platform into and out of said pocket independently of the elevation of said platform, the tops of said rails being at substantially the same height as the top of said platform when in its fully lowered position whereby said fully lowered platform may be moved horizontally into the space between said rails when in a fully loaded condition.

9. In a lift truck for load carrying pallets and the like, a vehicle frame having a pair of elongated side rails projecting transversely from one end thereof in parallel spaced relation to form a pocket therebetween, said pocket being vertically unobstructed from the ground up, a ground wheel rotatably mounted adjacent each of the outer ends of said side rails, said wheels being disposed for rotation in a plane longitudinal of said rails and being positioned to engage the ground and support said truck, a carriage mounted on said rails for horizontal movement longitudinally of said truck into and out of said pocket, and a pallet lift platform supported by said carriage for movement therewith, said platform being adapted for vertical movement from the ground up on said carriage independently of the position of said carriage, said rails being disposed at substantially the same elevation as the lowered platform.

10. In a lift truck adapted to carry loaded pallets and the like while traveling in a direction longitudinal of said truck, a vehicle frame having power means mounted thereon, a pair of elongated side rails projecting from one end of said frame substantially parallel to said line of travel, said rails being spaced to form a pocket therebetween which is vertically unobstructed from the ground up, a dirigible ground wheel disposed under said power means, a ground wheel rotatably mounted adjacent each of the outer ends of said side rails, said wheels being disposed longitudinally of said rails for rotation in planes parallel to said line of travel and being positioned to engage the ground and support said rails, a carriage mounted on said rails for horizontal movement longitudinally of said truck into and out of said pocket, a pallet lift platform supported by said carriage for movement therewith, said platform being adapted for vertical movement from the ground up on said carriage independently of the position of said carriage, the tops of said rails being at substantially the same height as the top of said platform when it is in its lowered position.

11. A material handling vehicle especially adapted for use in the storage of low ground clearance pick-up loads beside an aisle comprising a truck having a power unit section and load transporting section supported by ,said power unit section to project outwardly therefrom, said load transporting section including first support means carried by said power unit section and being disposed alongone side there of, said first support means including a pair of parallel spaced rails, the space between said rails forming an open ended pocket vertically unobstructed from the ground up, a second support means carried by said first support means and including a pallet lift platform of a size substantially corresponding to said space, one of said'support means being independently adaptable to move said platform in a vertical direction, the other of said support means being adaptable to extend and retract said platform in a horizontal direction into and out of said space for loading and unloading said vehicle.

12. In a material handling vehicle of the type described in claim 11 in which the other of said support means is adaptable to extend and retract said platform in a horizontal direction into and out of said space in all vertical positions of said platform for loading and unloading said" vehicle.

HOLDEN D. WOUGI-ITER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,900,569 Lederer Mar. 7, 1933 2,092,663 Bach Sept. 7, 1937 2,122,992 Pride July 5, 1938 2,126,289 Schroeder Aug. 9, 1938 2,320,601 Howell June 1, 1943 2,324,817 Bratley July 20, 1943 2,366,378 Barrett Jan. 2, 1945 2,437,806 Dempster Mar. 16, 1948 2,451,943 Gunning Oct. 19, 1948 2,492,608 Wilms Dec. 27, 1949 2,621,811 Lull Dec. 16, 1952 

